A chamber for annealing a semi-conductor material of II-VI type having a first area for storing an element of group II of the periodic table and a second area designed to receive the semi-conductor material of II-VI type. The chamber s equipped with a separating partition at the level of an intermediate area. This separating partition is provided with a passage aperture equipped with gas anti-reverse flow means to ensure one-way passage of the element of group II of the periodic table, in vapor phase, from the first area to the second area. This chamber is heated by heating means enabling the two areas to be heated independently.